package ftp;

import java.io.File;  
import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.InputStream;  
import java.io.OutputStream;  
import java.io.PrintWriter;  

import org.apache.commons.net.PrintCommandListener;  
import org.apache.commons.net.ftp.FTP;  
import org.apache.commons.net.ftp.FTPClient;  
import org.apache.commons.net.ftp.FTPFile;  
import org.apache.commons.net.ftp.FTPReply;  

import dataStruct.UploadStatus;
public class FtpApi {  
    private FTPClient ftpClient = new FTPClient();  

    public FtpApi(){  
        //设置将过程中使用到的命令输出到控制台  
        this.ftpClient.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));  
    }  

    /** 
     * java编程中用于连接到FTP服务器 
     * @param hostname 主机名 
     * @param port 端口 
     * @param username 用户名 
     * @param password 密码 
     * @return 是否连接成功 
     * @throws IOException 
     */  
    public boolean connect(String hostname,int port,String username,String password) throws IOException{  
        ftpClient.connect(hostname, port);  
        if(FTPReply.isPositiveCompletion(ftpClient.getReplyCode())){  
            if(ftpClient.login(username, password)){  
                return true;  
            }  
        }  
        disconnect();  
        return false;  
    }  

    /** 
     * 从FTP服务器上下载文件 
     * @param remote 远程文件路径 
     * @param local 本地文件路径 
     * @return 是否成功 
     * @throws IOException 
     */  
    public boolean download(String remote,String local) throws IOException{  
        ftpClient.enterLocalPassiveMode();  
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);  
        boolean result;  
        File f = new File(local);  
        FTPFile[] files = ftpClient.listFiles(remote);  
        if(files.length != 1){  
            System.out.println("远程文件不唯一");  
            return false;  
        }  
        long lRemoteSize = files[0].getSize();  
        if(f.exists()){  
            OutputStream out = new FileOutputStream(f,true);  
            System.out.println("本地文件大小为:"+f.length());  
            if(f.length() >= lRemoteSize){  
                System.out.println("本地文件大小大于远程文件大小，下载中止");  
                return false;  
            }  
            ftpClient.setRestartOffset(f.length());  
            result = ftpClient.retrieveFile(remote, out);  
            out.close();  
        }else {  
            OutputStream out = new FileOutputStream(f);  
            result = ftpClient.retrieveFile(remote, out);  
            out.close();  
        }  
        return result;  
    }  


    /** 
     * 上传文件到FTP服务器，支持断点续传 
     * @param local 本地文件名称，绝对路径 
     * @param remote 远程文件路径，使用/home/directory1/subdirectory/file.ext 按照Linux上的路径指定方式，支持多级目录嵌套，支持递归创建不存在的目录结构 
     * @return 上传结果 
     * @throws IOException 
     */  
    /**
     * @param local
     * @param remote
     * @return
     * @throws IOException
     */
    public UploadStatus upload(String local,String remote) throws IOException{  
        //设置PassiveMode传输  
        ftpClient.enterLocalPassiveMode();  
        //设置以二进制流的方式传输  
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);  
        UploadStatus result;  
        //对远程目录的处理  
        String remoteFileName = remote;  
        if(remote.contains("/")){  
            remoteFileName = remote.substring(remote.lastIndexOf("/")+1);  
            String directory = remote.substring(0,remote.lastIndexOf("/")+1);  
            if(!directory.equalsIgnoreCase("/")&&!ftpClient.changeWorkingDirectory(directory)){  
                //如果远程目录不存在，则递归创建远程服务器目录  
                int start=0;  
                int end = 0;  
                if(directory.startsWith("/")){  
                    start = 1;  
                }else{  
                    start = 0;  
                }  
                end = directory.indexOf("/",start);  
                while(true){  
                    String subDirectory = remote.substring(start,end);  
                    if(!ftpClient.changeWorkingDirectory(subDirectory)){  
                        if(ftpClient.makeDirectory(subDirectory)){  
                            ftpClient.changeWorkingDirectory(subDirectory);  
                        }else {  
                            System.out.println("创建目录失败");  
                            return UploadStatus.Create_Directory_Fail;  
                        }  
                    }  

                    start = end + 1;  
                    end = directory.indexOf("/",start);  

                    //检查所有目录是否创建完毕  
                    if(end <= start){  
                        break;  
                    }  
                }  
            }  
        }  

        //检查远程是否存在文件  
        FTPFile[] files = ftpClient.listFiles(remoteFileName);  
        if(files.length == 1){  
            long remoteSize = files[0].getSize();  
            File f = new File(local);  
            long localSize = f.length();  
            if(remoteSize==localSize){  
                return UploadStatus.File_Exits;  
            }else if(remoteSize > localSize){  
                return UploadStatus.Remote_Bigger_Local;  
            }  

            //尝试移动文件内读取指针,实现断点续传  
            InputStream is = new FileInputStream(f);  
            if(is.skip(remoteSize)==remoteSize){  
                ftpClient.setRestartOffset(remoteSize);  
                if(ftpClient.storeFile(remote, is)){  
                    return UploadStatus.Upload_From_Break_Success;  
                }  
            }  

            //如果断点续传没有成功，则删除服务器上文件，重新上传  
            if(!ftpClient.deleteFile(remoteFileName)){  
                return UploadStatus.Delete_Remote_Faild;  
            }  
            is = new FileInputStream(f);  
            if(ftpClient.storeFile(remote, is)){      
                result = UploadStatus.Upload_New_File_Success;  
            }else{  
                result = UploadStatus.Upload_New_File_Failed;  
            }  
            is.close();  
        }else {  
            InputStream is = new FileInputStream(local);  
            if(ftpClient.storeFile(remoteFileName, is)){  
                result = UploadStatus.Upload_New_File_Success;  
            }else{  
                result = UploadStatus.Upload_New_File_Failed;  
            }  
            is.close();  
        } 
        return result;  
    }  
    
    public Boolean download_chunk(String ftpFilePath, String slaverFilePath,
			Long offset, Long size) throws IOException {
		// TODO Auto-generated method stub
	      ftpClient.enterLocalPassiveMode();  
	        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);  

	        //debug
	        System.out.println(String.format("slaverFilePath = %s(FtpApi.java)",  slaverFilePath));
	        File f = new File(slaverFilePath);  
	        FTPFile[] files = ftpClient.listFiles(ftpFilePath);  
	        if(files.length != 1){  
	            System.out.println("远程文件不唯一");  
	            return false;  
	        }  

            FileOutputStream out = new FileOutputStream(f,true);  
            InputStream in = ftpClient.retrieveFileStream(ftpFilePath);
	      in.skip(offset);
            byte[] buf	= new byte [(int) (size + 1)];
            int start = 0;
            int len = size.intValue();
	        if(f.exists()){  
	            System.out.println("本地文件大小为:"+f.length());  
	            if(f.length() >= size){  
	                System.out.println("本地文件大小大于远程文件大小，下载中止");  
	                return false;  
	            }  
	            start = (int)f.length();
	            len -= start;
	        }  

	       in.read(buf, start, len);
           in.close();
	       //debug
	        System.out.println(String.format("buf = %s, start=%d, len=%d(FtpApi.java)",  buf.toString(), start, len));
	       out.write(buf, start, len);
            out.close();  

	        return true;
	}  
   
    public  synchronized UploadStatus upload_chunk(String slaverFilePath, String ftpFilePath,
    		Long offset, Long size) throws IOException {
            //设置PassiveMode传输  
            ftpClient.enterLocalPassiveMode();  
            //设置以二进制流的方式传输  
            ftpClient.setFileType(FTP.BINARY_FILE_TYPE);  
            if(ftpFilePath.contains("/")){  
                String directory = ftpFilePath.substring(0,ftpFilePath.lastIndexOf("/")+1);  
                if(!directory.equalsIgnoreCase("/")&&!ftpClient.changeWorkingDirectory(directory)){  
                    //如果远程目录不存在，则递归创建远程服务器目录  
                    int start=0;  
                    int end = 0;  
                    if(directory.startsWith("/")){  
                        start = 1;  
                    }else{  
                        start = 0;  
                    }  
                    end = directory.indexOf("/",start);  
                    while(true){  
                        String subDirectory =ftpFilePath.substring(start,end);  
                        if(!ftpClient.changeWorkingDirectory(subDirectory)){  
                            if(ftpClient.makeDirectory(subDirectory)){  
                                ftpClient.changeWorkingDirectory(subDirectory);  
                            }else {  
                                System.out.println("创建目录失败");  
                                return UploadStatus.Create_Directory_Fail;  
                            }  
                        }  

                        start = end + 1;  
                        end = directory.indexOf("/",start);  

                        //检查所有目录是否创建完毕  
                        if(end <= start){  
                            break;  
                        }  
                    }  
                }  
            }  

            FileInputStream in = new FileInputStream(slaverFilePath);  
           OutputStream out = ftpClient.storeFileStream(ftpFilePath);

            byte[] buf	= new byte [(int) (size + 1)];

     	       in.read(buf, 0, size.intValue());
               in.close();
               
    	       //debug
    	        System.out.println(String.format("buf = %s, offset=%d, size=%d(FtpApi.java)",  buf.toString(), offset.intValue(), size.intValue()));
    	        ftpClient.storeFile(ftpFilePath, in);
    	       out.write(buf, offset.intValue(), size.intValue());

             out.close();
		return UploadStatus.Upload_New_File_Success;  
	} 

    /** 
     * 断开与远程服务器的连接 
     * @throws IOException 
     */  
    public void disconnect() throws IOException{  
        if(ftpClient.isConnected()){  
            ftpClient.disconnect();  
        }  
    }
    
	public void delete(String ftpFilePath) throws IOException {
		ftpClient.deleteFile(ftpFilePath);
	}  

}
